fix(ask): supplier balances, payable per supplier per period, PDF fallback

- Ask's supplier loader didn't pass date_received, so supplier_balances
  and the supplier_balance dataset crashed
- supplier_balances takes a period (thisMonth, thisWeek, month1-3) and
  returns what was received from each supplier in it (payable)
- PocketBase's space-separated dates dropped deliveries on the 1st from
  period filters, including the Suppliers page's Payable KPI
- The PDF route falls back to the answer text when a saved report has
  no sections (older format), instead of a 500

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/api/ask/messages/[id]/pdf/route.ts

@@ -69,7 +69,13 @@ export async function GET(request: Request, { params }: { params: Promise<{ id:
 
   const date = new Date().toISOString().slice(0, 10);
   const preparedFor = `Prepared by Ask for ${actor.name}`;
-  const reportDoc = row.parsed?.pdf;
+  // Only a report with sections is built section by section. Reports
+  // saved in the older `{ title, subtitle, filename }` shape (before
+  // structured documents), or where the model sent no sections, fall
+  // back to the answer's own text — keeping the report's title.
+  const pdfMeta = row.parsed?.pdf;
+  const reportDoc =
+    pdfMeta && Array.isArray(pdfMeta.sections) && pdfMeta.sections.length > 0 ? pdfMeta : undefined;
 
   let buffer: Buffer;
   let title: string;
@@ -100,7 +106,8 @@ export async function GET(request: Request, { params }: { params: Promise<{ id:
       images,
     });
   } else {
-    title = (thread.title as string | undefined) || "Ask answer";
+    title = pdfMeta?.title || (thread.title as string | undefined) || "Ask answer";
+    filename = pdfMeta?.filename;
 
     const imageIds = new Set(Array.from(row.text.matchAll(IMAGE_TOKEN), (m) => m[1]));
     const images: ResolvedImage[] = [];

src/app/dashboard/financial/suppliers/page.tsx

@@ -4,6 +4,7 @@ import { Topbar } from "@/components/layout/sidebar";
 import { AddSupplierButton } from "@/components/supplier-form-dialog";
 import {
   computeSupplierBalances,
+  toIsoDate,
   type SupplierBalanceInput as In,
 } from "@/lib/metrics/supplier-balance";
 import { countsAsReceipt, type DocumentKind } from "@/lib/document-kind";
@@ -83,7 +84,9 @@ export default async function SuppliersPage({ searchParams }: { searchParams: Pr
     const qty = Number((line as { qty_received?: number }).qty_received ?? 0);
     const dateReceived = dateByDnId.get(dnId) ?? "";
     if (!dateReceived) continue;
-    deliveryValues.push({ dateReceived, value: round2(qty * rate) });
+    // ISO "T" form: PocketBase's space-separated date sorts before the
+    // period window's "T" and dropped deliveries on the 1st.
+    deliveryValues.push({ dateReceived: toIsoDate(dateReceived), value: round2(qty * rate) });
   }
 
   return (

src/lib/agent/format.ts

@@ -435,12 +435,14 @@ export interface SupplierBalancesResult {
   scope: string;
   supplierCount: number;
   showing: number;
-  totals: { display: { ordered: string; delivered: string; outstanding: string } };
+  /** Set when a period was asked for: the window and what was received in it. */
+  period?: { label: string; from: string | null; to: string | null };
+  totals: { display: { ordered: string; delivered: string; outstanding: string; receivedInPeriod?: string } };
   suppliers: {
     supplier: string;
     purchaseOrders: number;
     unresolvedDeliveryNotes: number;
-    display: { ordered: string; delivered: string; outstanding: string };
+    display: { ordered: string; delivered: string; outstanding: string; receivedInPeriod?: string };
     href: string;
   }[];
 }
@@ -451,10 +453,23 @@ export interface SupplierBalancesResult {
  */
 export function formatSupplierBalances(
   rows: SupplierBalanceRow[],
-  opts: { supplier?: string; limit?: number } = {},
+  opts: {
+    supplier?: string;
+    limit?: number;
+    /** Value received per supplier id in the period; rows with none are dropped. */
+    period?: { label: string; from: string | null; to: string | null; received: Map<string, number> };
+  } = {},
 ): SupplierBalancesResult | { error: string } {
   const q = (opts.supplier ?? "").trim().toLowerCase();
-  const matched = q ? rows.filter((r) => r.name.toLowerCase().includes(q)) : rows;
+  const byName = q ? rows.filter((r) => r.name.toLowerCase().includes(q)) : rows;
+  const received = opts.period?.received;
+  // With a period, "who do I pay" = suppliers with something received in
+  // it, largest first.
+  const matched = received
+    ? byName
+        .filter((r) => (received.get(r.id) ?? 0) > 0)
+        .sort((a, b) => (received.get(b.id) ?? 0) - (received.get(a.id) ?? 0))
+    : byName;
   if (q && matched.length === 0) {
     return {
       error: `No supplier matches "${opts.supplier}". Suppliers with the most outstanding: ${rows
@@ -466,14 +481,17 @@ export function formatSupplierBalances(
   let ordered = 0;
   let delivered = 0;
   let outstanding = 0;
+  let inPeriod = 0;
   for (const r of matched) {
     ordered += r.ordered;
     delivered += r.delivered;
     outstanding += r.outstanding;
+    inPeriod += received?.get(r.id) ?? 0;
   }
   const limit = opts.limit ?? 25;
   return {
     scope: q ? `suppliers matching "${opts.supplier}"` : "all suppliers",
+    ...(opts.period ? { period: { label: opts.period.label, from: opts.period.from, to: opts.period.to } } : {}),
     supplierCount: matched.length,
     showing: Math.min(limit, matched.length),
     totals: {
@@ -481,6 +499,7 @@ export function formatSupplierBalances(
         ordered: formatMoney(ordered),
         delivered: formatMoney(delivered),
         outstanding: formatMoney(outstanding),
+        ...(received ? { receivedInPeriod: formatMoney(inPeriod) } : {}),
       },
     },
     suppliers: matched.slice(0, limit).map((r) => ({
@@ -491,6 +510,7 @@ export function formatSupplierBalances(
         ordered: formatMoney(r.ordered),
         delivered: formatMoney(r.delivered),
         outstanding: formatMoney(r.outstanding),
+        ...(received ? { receivedInPeriod: formatMoney(received.get(r.id) ?? 0) } : {}),
       },
       href: `/dashboard/financial/suppliers/${r.id}`,
     })),

src/lib/agent/load.ts

@@ -557,12 +557,18 @@ export async function loadSupplierBalanceInput() {
       expand: "supplier",
       fields: "id,supplier,supplier_name_raw,status,stage,batch",
     }),
-    pb.collection("delivery_notes").getFullList({ fields: "id,document_type" }),
+    // date_received too: computeSupplierBalances needs both maps (the
+    // Suppliers page's period filter anchors on it). Missing it crashed
+    // Ask's supplier_balances tool.
+    pb.collection("delivery_notes").getFullList({ fields: "id,document_type,date_received" }),
   ]);
   const kindByDnId = new Map(
     deliveryNotes.map((d) => [d.id, (d.document_type ?? "") as DocumentKind]),
   );
-  return { suppliers, pos, items, deliveryLines, candidates, kindByDnId };
+  const dateByDnId = new Map(
+    deliveryNotes.map((d) => [d.id, (d.date_received ?? "") as string]),
+  );
+  return { suppliers, pos, items, deliveryLines, candidates, kindByDnId, dateByDnId };
 }
 
 /** Batch and note stages for the delivery-note inbox board counts. */

src/lib/agent/tools.ts

@@ -69,7 +69,8 @@ import {
 } from "./format";
 import { loadRainOutlook, type LocatableSite } from "@/lib/weather/load";
 import { countInboxColumns } from "@/lib/dn-pipeline/board";
-import { computeSupplierBalances } from "@/lib/metrics/supplier-balance";
+import { computeSupplierBalances, receivedInPeriodBySupplier } from "@/lib/metrics/supplier-balance";
+import { isInPeriod, PERIOD_OPTIONS, resolvePeriodWindow, type PeriodFilter } from "@/lib/supplier-period";
 import { groupAttendance } from "@/lib/attendance";
 import { computeSiteSummaries, toListSitesRow } from "@/lib/reports/site-summary";
 import { buildSiteReport } from "@/lib/reports/site-report";
@@ -966,15 +967,31 @@ export const tools: AgentTool[] = [
     schema: {
       supplier: z.string().optional().describe("Part of a supplier name; omit for all suppliers"),
       limit: z.number().optional().describe("Defaults to 25"),
+      period: z
+        .enum(["thisMonth", "thisWeek", "month1", "month2", "month3"])
+        .optional()
+        .describe(
+          "Only suppliers with goods RECEIVED in this period (by the delivery note's date received), with receivedInPeriod per supplier and in total — what is payable for that period, as on the Suppliers page. thisMonth = the current calendar month; month1/2/3 = one/two/three months back. Use for 'who do I need to pay this month'.",
+        ),
     },
     handler: async (args) => {
       const input = await loadSupplierBalanceInput();
-      const rows = computeSupplierBalances(
-        input as unknown as Parameters<typeof computeSupplierBalances>[0],
-      );
+      const typed = input as unknown as Parameters<typeof computeSupplierBalances>[0];
+      const rows = computeSupplierBalances(typed);
+      const period = typeof args.period === "string" ? (args.period as PeriodFilter) : undefined;
+      const window = period ? resolvePeriodWindow(period) : undefined;
       return formatSupplierBalances(rows, {
         supplier: args.supplier ? String(args.supplier) : undefined,
         limit: typeof args.limit === "number" ? args.limit : undefined,
+        period:
+          period && window
+            ? {
+                label: PERIOD_OPTIONS.find((o) => o.value === period)?.label ?? period,
+                from: window.fromISO?.slice(0, 10) ?? null,
+                to: window.toExclusiveISO?.slice(0, 10) ?? null,
+                received: receivedInPeriodBySupplier(typed, (iso) => isInPeriod(iso, window)),
+              }
+            : undefined,
       });
     },
   },

src/lib/metrics/supplier-balance.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { computeSupplierBalances } from "./supplier-balance";
+import { computeSupplierBalances, receivedInPeriodBySupplier, toIsoDate } from "./supplier-balance";
 
 describe("computeSupplierBalances", () => {
   it("rolls up each supplier's POs and counts open candidates, most outstanding first", () => {
@@ -56,3 +56,36 @@ describe("computeSupplierBalances", () => {
     expect(rows[0].outstanding).toBe(0);
   });
 });
+
+describe("receivedInPeriodBySupplier", () => {
+  const base = {
+    pos: [{ id: "po1", supplier_ref: "s1" }, { id: "po2", supplier_ref: "s2" }],
+    items: [
+      { id: "i1", purchase_order: "po1", qty: 10, rate: 100 },
+      { id: "i2", purchase_order: "po2", qty: 5, rate: 20 },
+    ],
+    deliveryLines: [
+      { purchase_order_item: "i1", qty_received: 3, delivery_note: "dnSep1" },
+      { purchase_order_item: "i1", qty_received: 2, delivery_note: "dnAug" },
+      { purchase_order_item: "i2", qty_received: 4, delivery_note: "dnSep20" },
+    ],
+    kindByDnId: new Map(),
+    dateByDnId: new Map([
+      ["dnSep1", "2026-09-01 00:00:00.000Z"],
+      ["dnAug", "2026-08-31 00:00:00.000Z"],
+      ["dnSep20", "2026-09-20 00:00:00.000Z"],
+    ]),
+  };
+  const september = (iso: string) => iso >= "2026-09-01T00:00:00.000Z" && iso < "2026-10-01T00:00:00.000Z";
+
+  it("splits value received in the period by supplier", () => {
+    const r = receivedInPeriodBySupplier(base, september);
+    expect(r.get("s1")).toBe(300);
+    expect(r.get("s2")).toBe(80);
+  });
+
+  it("counts a delivery on the 1st (PocketBase's space-separated date)", () => {
+    expect(receivedInPeriodBySupplier(base, september).get("s1")).toBe(300);
+    expect(toIsoDate("2026-09-01 00:00:00.000Z")).toBe("2026-09-01T00:00:00.000Z");
+  });
+});

src/lib/metrics/supplier-balance.ts

@@ -13,7 +13,7 @@
  * date ("we only pay what we received this month").
  */
 import { computeSupplierLedger } from "@/lib/supplier-ledger";
-import type { DocumentKind } from "@/lib/document-kind";
+import { countsAsReceipt, type DocumentKind } from "@/lib/document-kind";
 
 export interface SupplierBalanceRow {
   id: string;
@@ -113,3 +113,37 @@ export function computeSupplierBalances(input: SupplierBalanceInput): SupplierBa
   rows.sort((a, b) => b.outstanding - a.outstanding);
   return rows;
 }
+
+/** PocketBase writes "2026-09-01 00:00:00.000Z"; period windows use ISO "T". */
+export function toIsoDate(pbDate: string): string {
+  return pbDate.replace(" ", "T");
+}
+
+/**
+ * Value received per supplier (by supplier id) where the delivery note's
+ * `date_received` passes `inPeriod` — qty_received × the PO line's rate,
+ * receipt documents only. The same rule as the Suppliers page's "Payable
+ * this period" KPI, split by supplier, so Ask can answer "who do I pay
+ * this month".
+ */
+export function receivedInPeriodBySupplier(
+  input: Pick<SupplierBalanceInput, "pos" | "items" | "deliveryLines" | "kindByDnId" | "dateByDnId">,
+  inPeriod: (isoDate: string) => boolean,
+): Map<string, number> {
+  const supplierByPo = new Map(input.pos.map((p) => [String(p.id), p.supplier_ref ?? ""]));
+  const itemById = new Map(input.items.map((it) => [String(it.id), it]));
+  const out = new Map<string, number>();
+  for (const line of input.deliveryLines) {
+    const dnId = String(line.delivery_note ?? "");
+    if (!countsAsReceipt(input.kindByDnId.get(dnId) ?? "")) continue;
+    const date = input.dateByDnId.get(dnId) ?? "";
+    if (!date || !inPeriod(toIsoDate(date))) continue;
+    const item = itemById.get(String(line.purchase_order_item ?? ""));
+    if (!item) continue;
+    const supplierId = supplierByPo.get(String(item.purchase_order)) ?? "";
+    if (!supplierId) continue;
+    const value = Math.round(Number(line.qty_received ?? 0) * Number(item.rate ?? 0) * 100) / 100;
+    out.set(supplierId, (out.get(supplierId) ?? 0) + value);
+  }
+  return out;
+}